In recent years, small mobile products, such as a mobile phone, equipped with an imaging device (camera module) have become widely popular, and taking pictures instantly with the small mobile products has become a common practice. And as an imaging lens for small imaging devices incorporated in the small mobile products, an imaging lens composed of four lenses compatible with a high pixel imaging element having a megapixel or more has been proposed (see Patent document 1, for example).
The imaging lens described in Patent document 1 includes, in order from the object side to the image surface side, a first lens having positive power whose lens surface facing the object side is convex, a second lens having positive power, a third lens composed of a meniscus lens having negative power whose lens surface facing the object side is concave and a fourth lens composed of a meniscus lens having positive or negative power whose lens surface facing the object side is convex.